JPH08334073A - Hydraulically actuated type electronic control unit fuel injector (heui) with direct control type check - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately adjust the quantity of injected fuel under high pressure throughout a speed range and a load range by providing a check valve comprising a first and a second ball element, halfway in an injector bore and on the other end of a check provided with a sealing tip at the tip. SOLUTION: In this fuel injector, a check 66 provided at its tip with a sealing tip for cutting off a fuel passage by seating on a valve seat is disposed in an injector bore 64, and a movable valve element 96 is disposed around the other end 104 of the check 66. The movable valve element 96 is provided to surround a lower barrel 102 constituting a part of a stationary valve assembly 97 positioned between an upper barrel 90 and the upper surface 100 of the tip 78. A first and a second ball element 134, 136 are disposed respectively in a first chamber part 130 in the lower barrel 102 and a second chamber part 132 formed in the upper barrel 90 on the opposite side to the first chamber part 130 to form a check valve, thus measuring fuel.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates generally to fuel injectors. More specifically, it relates to HEUI fuel injectors having checks that are operated directly.

[0002]

2. Description of the Related Art Conventional fuel injection systems that can be used, for example, in diesel engines have generally been of the pump / pipe / injector type or unit injector type. Pump, plumbing and injector type fuel injection systems are available, for example, from 103 to 138 MPa (about 15,000 to 20,000 psi)
A main pump that pressurizes fuel to a high level like
A separate fuel injector connected to the pump by a fuel supply line. In a unit injector system, a low pressure pump delivers fuel to multiple unit injectors, each of which may, for example, be from 103 to 138 MPa (about 15,000
(Up to 20,000 psi), or even higher, to a relatively high value. One type of unit injector system, known as hydraulically actuated electronically controlled unit injector (HEUI), is known from Grassey US Pat.
No. 191,867. The working fluid in the form of engine oil is pressurized to an intermediate pressure of, for example, 20.7 MPa (3,000 psi) and supplied to each unit injector. An engine control module (ECM) produces injector actuation signals that are supplied to the solenoid windings of each injector. When the solenoid winding is excited by the ECM, the poppet causes the solenoid to move the flow of pressure working fluid to the pressure boost chamber. In response to the introduction of the pressurized working fluid into the chamber, the pressure boosting piston is displaced in a direction to pressurize the fuel in the high pressure chamber. The high pressure chamber is in fluid communication with a chamber that includes an elongated check that is spring biased toward the sealing surface to isolate the check chamber from the combustion chamber of the engine. When the pressure in the check chamber exceeds the valve opening pressure, which is determined by the spring force applied to the check, the check is lifted, thereby moving the check tip away from the sealing surface and delivering pressurized fuel to one or more combustors. Allows flow through the nozzle orifice into the corresponding engine combustion chamber. Degaussing the solenoid winding moves the poppet to a position that isolates the booster chamber from the pressurized working fluid, ending the injection. The pressure of the fuel in the high-pressure chamber drops sharply, which causes the spring to close the check against the sealing surface,
Fuel injection ends.

[0003]

The HEUI injection device is
While effective in controlling the introduction of pressurized fuel into the corresponding engine combustion chamber to approximately top dead center (TDC), such devices only indirectly control, that is,
The motive force to move the injector check is provided by the pressurized fuel itself rather than the directly controllable motive force source. Therefore, depending on the criteria of the relevant regulations, the degree of control capability required to reduce the harmful emissions of a particular gas to the desired degree is minimized. U.S. Pat. No. 5,421,521 issued to Gibson et al. On June 6, 1995 discloses a fuel injector having a force balance check movable between open and closed positions by means of a low force actuator. . This fuel injector has high controllability and can be used at high fuel injection pressures, which results in the desired reduction of undesirable exhaust gas harmful emissions.

[0004]

SUMMARY OF THE INVENTION A fuel injection system is a HEUI fuel having a device that is simple in design, uses robust, and reliable components, and that directly and quickly moves the fuel injector check. Equipped with an injector. More specifically, in one aspect of the invention, a fuel injection system operable to inject fuel into a combustion chamber during an engine cycle is coupled to a first pressurizing means for pressurizing a working fluid, the combustion chamber. And a means for coupling the pressurized injector with a fuel injector that supplies pressurized working fluid to the fuel injector for a duration less than or equal to an engine cycle. The fuel injector includes an elongated check having a second pressurizing means, a first check end and a second check end, and a check in response to a pressurized working fluid supplied for pressurizing the fuel. A second pressurizing means for controlling the fluid pressure supplied to the first check end and the second check end for a duration of time in order to move the first check end and the second check end to inject fuel into the combustion chamber. And a control means connected to the. It is preferred that the control means be provided with only two clearance fits where it is exposed to a large pressure difference only during the duration.

Desirably, fuel is injected into the combustion chamber only for a portion of the duration. Further, the fuel injector may desirably include a control valve having two clearance fits. Also preferably, one of the clearance fits is exposed to a large pressure differential for a portion of the duration and the other of the clearance fits is exposed to a large pressure differential for another portion of the duration. It is good to do so. further,
The first end of the check may be arranged in a bore within the stationary valve assembly and configured to define and form one of the clearance fits. In a special embodiment of the invention, the first pressurizing means comprises an oil pump. Further, the control means may include means for connecting to the second pressurizing means for delivering high pressure fuel to the second end of the check, and selecting either low pressure fuel or high pressure fuel at the first end of the check. A three-way control valve may be provided as applicable to the equation. In a preferred form of the invention, a three-way control valve includes a first bore for receiving a first end of a check, a first sealing surface and a second sealing surface separated by an intermediate surface, and a first end of the check. And a second bore in fluid communication between the intermediate surface and the intermediate surface. A movable valve element surrounds the valve assembly and connects a third sealing surface and a fourth sealing surface, a low pressure passage connecting the third sealing surface with a source of low fluid pressure, and a fourth sealing surface with a source of high fluid pressure. A high pressure passage is provided. The valve element has a first sealing surface in which the third sealing surface is in sealing contact with the first sealing surface and the first end of the check connects to a source of high fluid pressure, and a fourth sealing surface is in sealing contact with the second sealing surface. The first end of the check is moveable to and from a second position that connects to a source of low fluid pressure.

Furthermore, in a preferred embodiment, the three-way control valve further comprises an actuator operable to move the valve element between a first position and a second position, the actuator being of the piezoelectric type, for example. Can be a solid state motor such as. further,
The supply means may comprise a third bore within the valve assembly that provides fluid communication between the second pressurizing means and the second end of the check. The second pressurizing means may be composed of an actuatable plunger, and may further include a ball-type check valve connected between the actuatable plunger and the third bore. In another aspect of the invention, a fuel injector includes an injector body assembly, a three-way control valve having a valve element movable between first and second positions, and an injector body assembly. Placed on the fluid pressure applied to the ends so as to inject fuel into the combustion chamber when the control valve is in the second position and block fuel injection into the combustion chamber when the control valve is in the first position. It is equipped with a check that can be moved accordingly. The actuator is selectively actuatable to move the valve element between a first position and a second position, the injector is actuable during each of a plurality of injector cycles, and the control valve is With only one pair of clearance fits, the clearance fits are exposed to large pressure differentials only during a portion of each injector cycle.

In yet another aspect of the present invention, a fuel injector has a first end and a second end, the first and second ends being for injecting fuel into a combustion chamber. It comprises an elongated check movable in response to the applied fluid pressure and means for arranging the second end of the check in fluid communication with a source of high fluid pressure. The stationary valve assembly includes a first bore for receiving a first end of the check, a first sealing surface and a second sealing surface separated by an intermediate surface, and fluid communication between the first end and the intermediate surface of the check. A second bore is provided. A movable valve element surrounds the valve assembly and connects a third sealing surface and a fourth sealing surface, a low pressure passage connecting the third sealing surface with a source of low fluid pressure, and a fourth sealing surface with a source of high fluid pressure. A high pressure passage is provided. The valve element has a first sealing surface in which the third sealing surface is in sealing contact with the first sealing surface and the first end of the check is connected to a source of high fluid pressure, and a fourth sealing surface is in sealing contact with the second sealing surface. The first end of the check is moveable to and from a second position connected to a source of low fluid pressure. The actuator is operable to move the valve element between a first position and a second position. Since the fuel injector check of the present invention is directly controlled, a fuel injection configuration that reduces undesired harmful emissions in engine exhaust gases can be used. Furthermore, the fuel injector according to the invention comprises a clearance type leak passage, which is exposed to high supply pressure differences for only a few of each engine cycle. Therefore, leakage is greatly reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a hydraulically actuated electronically controlled unit injector (HEUI) system 10 includes a fuel tank 1
4 and filter 16 receive fuel, for example about 0.414M
A transfer pump 12 is provided for delivering fuel to a fuel injector 18 through a fuel rail line or conduit 20 at a relatively low pressure such as Pa (60 p.si). Working fluid, such as engine oil, supplied from the engine sump is pressurized by pump 22 to an intermediate standard pressure, such as 20.7 MPa (3,000 psi). A rail pressure control valve 24 may be provided to regulate the oil pressure applied to the injector 18 through the oil rail line or conduit 26 by the level of the signal provided by the electronic engine controller 28. Depending on the electronic control signal generated by the engine controller 28, for example, 138 MPa (20,000 ps)
i.), or at a higher pressure, fuel injector 18
Inject fuel into a combined combustion chamber or cylinder (not shown) of an internal combustion engine. Although six fuel injectors 18 are shown in FIG. 1, as an alternative, another number of fuel injectors may be used to inject fuel into the same number of combined combustion chambers. Also, the engine that can be used with the fuel injection system 10 is a diesel cycle engine, an ignition engine, or any other type that requires or desires fuel injection.

If desired, the fuel injection system 10 of FIG.
May be modified by adding another fuel supply line or another oil supply line extending between the pumps 12, 22 and each injector 18. In other cases, or in addition, fuel or other fluids may be used as the working fluid and, if desired, the timing and injection of the injectors may be by a mechanical or hydraulic device rather than the engine controller 28. The duration may be controlled. A prior art fuel injector 18 usable with the fuel injector system 10 of the fuel injector of FIG. 1 is shown in FIG. Grassey US Patent No.
The fuel injector is disclosed in US Pat. No. 5,191,867, which is incorporated by reference for a detailed description of the injector. The fuel injector 18 includes a check 30 that resides in an injector bore 32 located within the injector body 33. The check 30 comprises a sealing tip 34 arranged at the first end 36 and an expansion plate or expansion head 38 arranged at the second end 40. Spring 42 biases sealing tip 34 against valve seat 44 to isolate fuel chamber 46 from one or more nozzle orifices 48, as shown in enlarged detail in FIG.

The fuel injector 18 further includes a fuel supply line.
A fuel inlet passage 50 disposed in fluid communication with.
Fill the corresponding cylinders with fuel, as detailed in FIG.
When injecting, check the pressurized fuel through the passage 50
30 into the space between the injector bore 32 and the fuel chamber 46
Sent to. Pressure P in the fuel chamber 46_INJIs selected
When the lube opening pressure (VOP) is reached, the check lift
Occurs from the valve seat 44 to the sealing tip 34.
And the pressurized fuel is assembled through the nozzle orifice 48.
It flows out into the combined combustion chamber. The pressure VOP is as follows
Specified in. VOP: S / A1 · A2 where S is the load applied by the spring 42,
A1 is the cross-sectional dimension of the valve guide 52 of the check 30.
A2 is due to the contact between the valve seat 44 and the sealing tip 34.
It is the diameter of the wire formed. Check lift time
After that, the pressure P in the injector tip chamber 56 is increased._SACIs increasing
And then until the check 30 reaches the point of returning to the closed position.
Then, the pressure P in the combustion chamber 46 _INJDepending on the selected
The valve closing pressure (VCP) is reduced. The pressure VCP is
Determine according to the formula below.

VCP: S / A1 As previously mentioned, where S is the spring load exerted by spring 42 and A1 is the cross-sectional diameter of valve guide portion 52 of check 30. As mentioned above, opening and closing of the fuel injector 18 is accomplished only indirectly, for example, only by the force produced by delivering pressurized fuel to the injector bore 32. One consequence of this fact is that the injector opening pressure VOP and the injector closing pressure VCP are preselected in the overall injector design and cannot be easily changed. In addition, accurate fuel measurements must be performed to reduce gaseous and particulate toxic emissions. However, Grassey's US patent
With the use of pressure actuated check injectors as described in 5,191,867, this purpose is a challenge. A fuel injector 60 according to the present invention that can be used as the fuel injector 18 in the system of FIG. 1 is shown in FIGS. Alternatively, if desired, a major feature of injector 60, the means for moving the check directly and quickly, may be modified to a type known to those skilled in the art for use with other fuel systems. May be.

The fuel injector 60 includes an injector body assembly 61 having an injector case 62 and an injector cavity 64. The elongated check 66 is located within the injector cavity 64 and is movable between a closed position in which fuel is not injected into the combined combustion chamber 68 and an open position in which fuel is injected into the combined combustion chamber 68. Is. When the check 66 is in the first position, the tip 74 of the check 66 seals against the seat 76 within the tip 78 of the injector 60. With particular reference to FIG. 6, the injector 60 further includes an actuator 80 that couples to a three-stage control valve 82 that is placed in fluid communication with the check 66.
In the preferred embodiment, the actuator 80 comprises a semiconductor motor 84 having a plurality of piezoelectric elements disposed and stacked within a recess 86. If desired, actuator 80 may be of another type, eg, solenoid. A stack of piezoelectric elements surrounds an upper barrel 90 having a fuel passage 92 therethrough. Semiconductor motor 84 and upper barrel 90
Are arranged between the upper body member 94 and the movable valve element 96 and the stationary valve assembly 97. Movable valve element 96 includes upper surface 10 of tip 78 of injector 60.
It is biased to the upper or first position by a dish washer 98 which supports 0.

Movable valve element 96 is located in lower barrel 1 between upper barrel 90 and upper surface 100 of tip 78.
Surround 02. Lower barrel 102 comprises a portion of stationary valve assembly 97. The check 66 comprises an upper or first end 104 that is snugly fitted and disposed in a sliding relationship within a bore or passage 106 in the lower barrel 102 to form a loose fit therebetween. As a result, the lower barrel 102 acts as a guide for the check 66. The stationary valve assembly 97 further includes a seat 1 supported by a first sealing surface and a second sealing surface, ie, the upper barrel 90 and the lower barrel 102, respectively.
08, 110 and an intermediate surface 112 supported by the lower barrel 102. Second bore or passage 11
4 extends between the bore 106 and the intermediate surface 112 and is in fluid communication between the first end 104 of the check 66 and the intermediate surface 112. The lower barrel 102 further includes a third bore or passage 115 extending between the chamber 116 and the injector cavity 64 such that the second or lower end of the check 118 including the tip 74 is in fluid communication with the fuel passage 92. . In addition, the fourth bore or passage 120 includes the bore 11
5 and the high pressure ring 122 formed in the movable valve element 96.
Extend between and.

A low pressure annulus 124 is formed in the movable valve member 96 that connects to a low pressure source such as a tank by a bore or passage 126, an annulus 127, and an outlet 128 (FIG. 6). The chamber 116 comprises a chamber first portion 130 in the lower barrel 102 and a chamber second portion 132 formed in the upper barrel 90 opposite the chamber first portion 130. A first ball element 134 and a second ball element 136 are disposed within the chamber first portion 130 and the chamber second portion 132, respectively, and mate with the walls forming the chamber first portion 130 and the chamber second portion 132 by a spring 138. Force outwards as you would. The spring 139 is arranged in compression between the first ball element 134 and the upper end 104 of the check 66. As described in detail below, ball elements 134, 1
The wall forming 36 and chamber portions 130, 132 form an optional check valve. Referring again to FIGS. 5 and 6, the upper body member 94 includes a bore 140 in which the plunger 142 of the booster assembly 144 is located. The booster assembly 144 further includes an upper piston 146 having a hollow interior surface and a groove 152 in the plunger 142.
A washer 150 supported in the upper body member 9
4 and a spring 148 disposed between the upper surface 154 and the upper surface 154. Piston 146 is located within cylinder 156, which is connected to spool valve 160 by passage 158. The spool valve 160 includes an axially movable spool 162 that connects to the armature of the solenoid 164. Spool 162 is movable by solenoid 164 to provide fluid communication between high pressure annulus 168 that receives oil from an oil pressure source, such as oil pump 22 and rail pressure control valve 24 of FIG. 1, and passage 158. , The low pressure ring 170 connected to the sump through the passage 1
Reduced diameter portion 16 movable to connect with 58
6 is provided.

Referring first to FIG. 5, an explosion occurs once during an engine cycle (that is, once every two revolutions of a four-cycle engine crankshaft or once every two revolutions of a two-cycle engine crankshaft). In time, a solenoid 164 is activated by a controller, such as the engine controller 28 of FIG. 1, to axially move the spool 162 so that the reduced diameter portion 166 interconnects the high pressure annulus 168 to the passage 158. . Pressurized oil
The top of the piston 146 is pushed down, which causes the plunger 142 to move downstream as well, causing the fuel inlet 171,
Inlet ring 172, passage 173, and check valve 174
The fuel fed to the bore 140 is pressurized.
The pressure of the fuel in the bore 140 is, for example, 138 MPa (20,000
psi) or higher pressure. Pressurized fuel is passed through the fuel passages 92 and through the balls 136 to the second bore 115 and the cavity 64. Pressurized fuel is also delivered to the high pressure ring 122 through the fourth bore 120. Desirably, this pressurization provides a duration during which injection proceeds only during 40 to 50 engine cycles. During all other periods of each engine cycle (i.e. for the rest of the period where two crankshaft revolutions are required on a 4-stroke engine or one crankshaft revolution on a two-stroke engine). The solenoid 164 is activated to place the reduced diameter portion 166 of the spool 162 in a position that connects the constant pressure ring 170 of the spool valve 160 to the passage 158 (for the remainder of the required period).

During the time that pressurized oil is supplied to booster assembly 144, solid state motor 84 is operated by engine controller 28 by the generation and application of drive pulses of appropriate magnitude and duration thereto. It Prior to actuation of the solid state motor 84, the upper or first end 104 of the check 66.
Is connected to the high pressure fuel in the high pressure ring 122 by the second bore 114, and further, the sealing surface 175 of the movable valve element 96.
By contacting the first sheet 108 with the low pressure ring 12
Isolate from 4. When the solid state motor 84 is activated, downstream pressure is applied to the moveable valve element 96,
The intermediate surface 112 moves from a first position shown in FIG. 7 in fluid communication with the high pressure ring 122 to a second position in which the intermediate surface 112 is placed in fluid communication with the low pressure ring 124. As the moveable valve element 96 moves downstream, the sealing surface 176 makes sealing contact with the second seat 110, and the sealing surface 175 becomes the first seat 108.
Move to get out of contact with. Intermediate surface 112,
Therefore, the second bore 114 and the first end 104 of the check 66 are placed out of fluid communication with the high pressure ring 122 and in fluid communication with the low pressure ring 124. At the same time, check 6
The second or lower end of 6 remains exposed to the high pressure fuel due to trapping of such fuel in passage 115 and cavity 64, this pressure imbalance being the force provided by spring 139. Force is generated to displace the check 66 upstream so that the pressurized fuel leaks into the combustion chamber 68.

When fuel injection is to be terminated, the signal provided to the solid state motor 84 is removed, which causes the moveable valve element 96 to move upstream under the influence of the dish washer 98. As a result, the sealing surface 176 comes out of contact with the sheet 110 and the sealing surface 175 is moved into sealing contact with the sheet 108. The second bore 114, and thus the first end 104 of the check 66, is placed in fluid connection with the high pressure ring 122.
At the same time, even when the check 66 is in the open position, the pressurized fuel is released from the fuel passage 92 through the ball 136 to the third and fourth bores 115, 120 and the high pressure ring 122. As a result, the pressures applied to the first end 104 and the second end 118 of the check 66 are equal and the fluid forces on the check 66 cancel each other out. Therefore, the check 66 moves downstream under the influence of the spring 139 so that the end 74 of the check 66 seals against the seat 76 in the end 78 of the injector. A check valve formed by a ball 134 disposed in the combustion chamber first portion 130 is provided so as to provide a smooth flow obstruction that occurs during operation of the fuel injector. When no such flow obstruction is encountered, the ball 136 may move into the chamber second portion 13
This element is optional in the sense that it may be entirely replaced by a wall separating the upper end 104 of the check 66 from 2. In this case, the spring 139 is placed in compression between such a wall and the check end 104.

In addition, the check valve formed by ball 136 is also optional and, if desired,
It may be omitted. Referring to FIG. 7 in detail, the control valve 82 has only two clearance fits, namely the check 6
2 of the first clearance fit 180 between the upper end 104 of 6 and the wall forming the bore 106 and the second clearance fit 182 between the surface 184 of the lower barrel 102 and the wall 186 of the movable valve element 96. Only have one. These clearance fits are
Only during the period when hydraulic oil is supplied to the piston 146 under pressure is it exposed to a large pressure difference. In particular, the fuel in the fuel passage 92 is pressurized and the solid state motor 84
The high-pressure fuel was present in the high-pressure ring 122 during the period when the fuel cell does not operate, but the fuel pressure in the recess 188 is low,
This creates a large pressure differential across the clearance fit 182. When the motor 84 operates, the pressure differential across the clearance fit 182 eventually disappears, and the relatively low fuel pressure in the second bore 114 and the passage 115 and the cavity 64.
Due to the high fuel pressure within, a large pressure differential occurs before and after the clearance fit 180. In the preferred embodiment of the injector, the pressurization condition is maintained for a short period of time during any other revolution of the engine crankshaft, and the pressurization condition is eliminated by deactivating solenoid 164. , The pressure difference acting on the clearance fits 180, 182 is eliminated. Thus, the possibility of fuel leakage is reduced not only by the amount of time the injector is pressurized, but also by the fact that there are only two clearance fits in the control valve 82.

The injectors shown in FIGS. 5-7 are supplied with a working fluid "force", such as engine oil, to pressurize the fuel and use electrical signals to control the timing and duration of the injection. Specifically adapted for use in a HEUI fuel injection system. Such a device can independently control the injection duration with the injection pressure and consequently have a greater controllability. However, as noted above, fuel pressurization may be accomplished in other ways, such as by utilizing a mechanical connection to a rocker arm or engine camshaft, or by other means. be able to. Also, control of the fuel injector may be accomplished by electrical means, other than via the use of hydraulically or mechanically actuated assemblies, for example. The present invention directly controls the check motion and significantly improves the fuel measurement capability even at very high fuel pressures throughout the engine's speed and load ranges. Therefore, the ability to reduce hazardous emissions is improved. Also, the high pressure fuel is only available for injection for a short period of time in each engine cycle, thus providing energy savings and reducing or eliminating the possibility of fuel overuse due to nozzle check leaks. To do.

Many variations and other embodiments of the invention will be apparent to those skilled in the art in the manner of the foregoing description. The above description is illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of construction and method may be varied without departing from the spirit of the invention, and include all modifications within the scope of the appended claims.

[0021]

【The invention's effect】 [Brief description of drawings]

FIG. 1 is a combined schematic block diagram of a conventional supply rail fuel injection system.

FIG. 2 is a partial cross-sectional elevational view of a prior art fuel injector.

3 is an enlarged partial cross-sectional view of the fuel injector of FIG.

FIG. 4 is a graph showing the operation of the fuel injector of FIG.

FIG. 5 is a detailed cross-sectional view of a fuel injector according to the present invention.

6 is an enlarged partial cross-sectional view of the injector of FIG.

7 is an enlarged partial cross-sectional view of the injector of FIG.

[Explanation of symbols]

10 Hydraulically operated electronic control unit injector (HEUI)
System 12, 22 Pump 14 Fuel tank 16 Filter 18, 60 Fuel injector 20, 26 Conduit 24 Rail pressure control valve 28 Engine control device 30, 66, 74, 78, 118 Check 32, 106, 114, 115, 120, 126 , 14
0 Bore 33 Injector body 34 Sealing tip 36, 40, 104 End 38 Expansion head 42, 138, 139 Spring 44 Valve seat 46, 56, 116 Chamber 48 Nozzle orifice 50, 92, 120, 158, 173 Passage 52 Valve guide 61 injector body assembly 62 injector case 64 injector cavity 68 combustion chamber 76, 108, 110 seat 80 actuator 82 three-stage control valve 84 motor 86 recess 90, 102 barrel 94 body member 96 valve element 97 stationary valve assembly 98 Dish-shaped washers 100, 112, 154 Surfaces 122, 124, 127, 168, 170 Rings 126 Passages 128 Outlets 130, 132 Chamber parts 134, 136 Ball elements 142 Plungers 144 Pressure booster assemblies 146 Pistes 150 Washer 152 Groove 156 Cylinder 160 Spool valve 162 Spool 164 Solenoid 166 Diameter part 171 Fuel inlet 172 Inlet ring 174 Check valve

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location F02M 61/10 F02M 61/10 MS 61/12 61/12 H01L 41/09 H01L 41/08 C (72) Inventor Donald Jay Waldman United States Illinois 61517 Brimfield Schilling Road 14409 (72) Inventor Scott F Shaffer United States Illinois 61550 Morton North Kansas Avenue 248

Claims (19)

[Claims] 1. A HEUI fuel injection system operable to inject fuel into a combustion chamber during an engine cycle, the first pressurizing means for pressurizing a working fluid, and the fuel connected to the combustion chamber. An injector, and a supply means connected to the fuel injector for supplying a pressurized working fluid to the fuel injector for a duration of the engine cycle or less, the fuel injector adding fuel. A second pressurizing means responsive to the pressurized working fluid supplied during a pressing duration, an elongated check having a first check end and a second check end, and moving the check to an open position. During the duration, the first check is performed so that a clearance fit provided with only two causes fuel to be injected into the combustion chamber which is exposed to a large pressure difference for the duration. Parts and fuel injection system comprising a control means, the coupling to the second pressurizing means for controlling the fluid pressure supplied to the second check end. 2. The fuel injection system according to claim 1, wherein fuel is injected into the combustion chamber only during a part of the duration. 3. The control means comprises a control valve having two said clearance fits.
The fuel injection system according to. 4. One of the clearance fits experiences a large pressure difference during the portion of duration and the other of the clearance fits experiences a large pressure difference during another portion of the duration. The fuel injection system according to claim 3, wherein: 5. The fuel injection system of claim 3, wherein the first end of the check is located within a bore within the stationary valve assembly to define the one of the clearance fits. 6. The fuel injection system according to claim 1, wherein the first pressurizing means includes an oil pump. 7. The means for connecting the control means to the second pressurizing means for delivering high pressure fuel to the second end of the check, and either the high pressure fuel or the low pressure fuel at the first end of the check. The fuel injection system according to claim 1, further comprising a three-way control valve that selectively applies one of them. 8. The three-way control valve includes a first bore for receiving the first end of the check, a first sealing surface and a second sealing surface separated by an intermediate surface, and the first end of the check. A stationary valve assembly having a second bore in fluid communication between the intermediate surface and the intermediate surface; a third sealing surface and a fourth sealing surface surrounding the valve assembly; A low pressure passage connected to the three sealing surfaces and a high pressure passage connecting a source of high fluid pressure to the fourth sealing surface, the third sealing surface in sealing contact with the first sealing surface, A first position at which a first end connects to the source of high fluid pressure, the fourth sealing surface in sealing contact with the second sealing surface, and the first end of the check to the source of low fluid pressure. A movable valve element movable between a second position for connection and a second position for connection. The fuel injection system according to claim 7, characterized in. 9. The three-way control valve further comprising an actuator operable to move the valve element between the first position and the second position. Fuel injection system. 10. The fuel injection system according to claim 9, wherein the actuator includes a semiconductor motor. 11. The fuel injection system according to claim 10, wherein the semiconductor motor is of a piezoelectric type. 12. The delivery means comprises a third bore disposed within the valve assembly in fluid communication between the second pressurizing means and the second end of the check. Item 8. The fuel injection system according to Item 8. 13. The fuel injection system according to claim 12, wherein the second pressurizing means comprises an actuatable plunger. 14. The fuel injection according to claim 13, wherein the second pressurizing means further comprises a ball-type check valve connected between the actuatable plunger and the third bore. system. 15. An injector body assembly, a three-way control valve having a valve element moveable between a first position and a second position; and a control valve disposed within the injector body assembly, Depending on the fluid pressure applied to the end, injecting fuel into the combustion chamber when in the second position and interrupting fuel injection into the combustion chamber when the control valve is in the first position. Movable check, and an actuator selectively actuable to move the valve element between the first position and the second position,
In each of a plurality of injector cycles, the injector is operable and the control valve comprises only a pair of clearance fits, the clearance fits being only during a portion of each injector cycle. Hydraulically actuated electronic control unit fuel injector exposed to large pressure differences. 16. The fuel injector according to claim 15, wherein the actuator comprises a solid state motor operable to move a piston to mate with the valve element. 17. The three-way control valve further comprises: a first bore for receiving the first end of the check and a first sealing surface and a second sealing surface separated by an intermediate surface; and the first end of the check. A stationary valve assembly having a second bore in fluid communication with the intermediate surface, the valve element surrounding the valve assembly, a third sealing surface and a fourth sealing surface, and a source of low fluid pressure. A low pressure passage connecting the third sealing surface to the third sealing surface and a high pressure passage connecting a source of high fluid pressure to the fourth sealing surface, wherein the valve element has the third sealing surface being the first sealing surface. A first position in sealing contact with the first end of the check connected to the source of high fluid pressure, the fourth sealing surface in sealing contact with the second sealing surface and the first end of the check Transfer to and from a second position connected to the source of low fluid pressure The fuel injector according to claim 15, wherein the fuel injector is movable. 18. The fuel injector according to claim 17, comprising means for delivering high pressure fuel to the second end of the check. 19. The fuel injector of claim 18, wherein the delivery means comprises a third bore located within the valve assembly.